A conventional rotary compressor employed in an air-conditioner comprises a cylinder, a roller eccentrically revolvable within the cylinder, and a vane inserted in a travelable manner into a through hole formed in a radial direction of the cylinder and slidable with regard to the roller. In general, the vane is made of a special iron system material having excellent abrasion-resistance and which has undergone heat treatment.
In recent years, the vane, roller and cylinder have been required to meet more severe sliding conditions, and the coolant has been replaced with R22 substitutes to prevent the ozone layer from being destroyed. Under these circumstances, elements with excellent abrasion-resistance are desirably used. The vane has been made of special steel including SKH51 (specified by Japanese Industrial Standard, hereinafter referred to as JIS), special casting, or sintered iron system material; however, these respective materials cannot satisfy the more severe conditions from a standpoint of abrasion-resistance.